A person communicating via a telecommunications network often uses a conventional stationary deskphone, which is convenient to use as it has a big keypad and a big display. The person can use stationary deskphones when moving between different locations, but then subscriptions, rights, identities etc belonging to other persons are utilized. Instead, when moving the person can use a mobile telephone, which is small and is easy to carry around. The mobile telephone on the other hand has a small keypad that can be a bit difficult to use and has a tiny display that can be hard to view. The sound quality and the volume are not always excellent for a mobile telephone but are nearly always so for a deskphone. The handset for the deskphone is often regarded as more convenient to hold than the small mobile telephone. This leads to a situation where people have both a mobile telephone to carry around and a stationary deskphone in the office. The person has separate accesses although one would have been enough and the person also must have multiple sets of user data in the telephony system. Multiple directory numbers can be confusing for other persons. Also, the deskphone still requires the person to be tied to a particular telephone line, and if the person moves permanently the user data have to be changed.
The European patent application EP 0 930 766 A2 discloses a system for radio communication between a wireless LAN and a PBX. The wireless LAN has remote devices, which have radio access to the PBX and can use its different features. In an embodiment the remote device is a cash register which is cable connected to a mobile phone. The latter is in turn radio connected to the PBX. In an alternative the phone is a wireless phone which communicates with the cash register by digital radio communication.
In the U.S. Pat. No. 5,726,984 is disclosed a communication system including a LAN, which has radio access points. Computing devices are in radio contact with the access points and peripheral devices, such as printers, are radio connected to the computing devices. The patent also discloses stationary telephones which are wire connected to radio access devices. The latter are in turn radio connected to the LAN, which is a wired backbone LAN.